PROJECT SUMMARY Alcohol use disorder (AUD) is one of the foremost public health problems. Available medications do not meet the needs for treating AUD. Glucagon-like peptide 1 (GLP1) is a major incretin that controls glucose homeostasis. GLP1 receptor agonists can also attenuate the reinforcing properties of alcohol in rodents. We have developed a novel mouse-to-mouse skin transplantation method that allows the stable introduction of engineered epidermal progenitor cells into immunocompetent hosts. This technical advancement enabled us to use the CRISPR technology to target a doxycycline (dox)-inducible expression cassette encoding a modified GLP1 (DImGLP1) into mouse epidermal progenitor cells and to transplant the engineered cells into mice. Upon dox exposure in vivo, DImGLP1 mice did not develop ethanol-induced conditioned place preference, supporting feasibility of the cutaneous inducible mGLP1 gene approach to counter rewarding effects of alcohol. To further reduce potential side effects of sustained mGLP1 expression and to achieve ethanol-specific induction of mGLP1, we have made an ethanol-inducible (EI) expression system in mice. When engineered in epidermal progenitor cells, the EI system allowed a sensitive, rapid and transient induction of the reporter gene expression when exposed to ethanol. The goal of this multi-PI exploratory proposal is to take advantage of the novel EI platform to develop an innovative cutaneous gene therapy for several key aspects of AUD in mice. We propose to determine whether grafting EImGLP1 cells in C57BL/6J mice and in high-alcohol preferring mice protects them from ongoing ethanol-taking and excessive drinking, reduces ethanol-induced rewarding effects and reinstatement of ethanol-seeking, and how long EImGLP1-grafts and EImGLP1 expression remain effective in vivo. We expect the proposed cutaneous gene therapy to be long-lasting and efficient with little individual variation. To be able to engineer a stable in vivo bio-delivery system for an EImGLP1 gene via epidermal progenitor cells is highly significant because it may provide a valuable addition to existing approaches for reducing ongoing alcohol use, abuse and relapse in users and addicts. The proposed work will have a high impact in that results will lay key groundwork for the development of a highly personalized and long-lasting approach for combating AUD.